Currently bundles and kits work identically in Configured commerce - allowing you to create a BOM. I have reached out to support and they tell me these are identical features so I'm not sure why they both exist in Configured commerce. For users who have integrated to an ERP this feature is not usable as you need the item in your ERP to accept an order, at which point you would just make it in your ERP.
The use case for bundles as described in Commerce Connect is perfect for Configured commerce users who have integrated with an ERP. Specifically building a temporary BOM for the user to select/buy but then adding the individual components to the cart. this way you can create one off bundles that don't exist in the ERP.
Additionally this would clear up the confusion on why you have two identical features (bundles/kits in CC and standardize the bundle feature in both platforms.